Fitness trends may come and go, but our dedication to running never seems to falter. With many of us obsessively training for marathons each year, each hoping to not only complete the impressive feat but also achieve a personal best, attention has recently turned to just how fast it is humanly possible to run a marathon. No one has yet achieved a time of under two hours, but can it be done?

Sports giant Nike has recently turned its focus to the challenge, setting out to break the 2-hour marathon barrier with its new project Breaking2.

The brand has recruited three top athletes for the feat: Eliud Kipchoge of Kenya, Lelisa Desisa of Ethiopia and Zersenay Tadese of Eritrea, who have all been chosen for their potential to break the men's world record time, currently set at 2:02:57 by Kenyan Dennis Kimetto at the Berlin Marathon in 2014.

The new aim would require knocking three per cent off the existing time, equal to shaving seven seconds off each of the 26.2 miles of the marathon. Even for the world's best runners this is a huge difference, and many believe it can't be done. But what does science say?

According to new research from the University of Colorado Boulder, a series of mathematical calculations show that the two-hour time could be broken, and not only by shaving three per cent off the existing time, but by taking off an impressive four and a half minutes.

First of all, athletes would need to think about their shoes. When Kimetto broke the record he was wearing trainers that weighed 230g, or just over eight ounces each. A previous study showed that running in 130-gram shoes could shave 57 seconds off a marathon time. This is a factor Nike is also surely set to consider, having announced that sports gear will be one of the areas they are looking into as part of Breaking2.

In addition, during the first 13 miles of the race an elite runner would achieve a better time running a loop course on a route that blocks the wind, and behind a wedge of marathon "pacemakers" to also reduce air resistance. If runners ran in a line, taking turns to block air resistance, three minutes could be shaved off the time, as could a strong tailwind approaching 13 mph if the runners had luck on their side.

For the second half of the race the course should be also slightly downhill but still within the regulations of the International Association of Athletics Federations (IAAF).

Nike has also been considering such factors, announcing on Wednesday that the location of their Breaking2 attempt is, as the research suggests, a fixed looped course located at the Autodromo Nazionale Monza complex outside Monza, Italy.

The track will give runners an optimum consistency to run on and provides an even pitch throughout the loop, which at 2.4 km long allows for perfect management of pacing, hydration, and nutrition.

The location has also been chosen for its weather conditions, with a temperature which stays at around 12 degrees and typically overcast skies to minimize the heat bearing down on the runners. As the research pointed out air currents are also important, with Nike also opting for the track due to its stable currents with no drastic directional shifts.

With many other factors still to consider if the record is to be broken, Nike is employing a team of experts to also look at biometrics, training, nutrition, sports psychology and more. In the meantime running fans will have to wait until next year for the date of the sub two-hour race attempt, but the progress of Breaking2 can be followed on Nike's dedicated website.